Nevo displásico (nevo atípico) Dysplastic nevus (atypical nevus)

O nevo atípico (displásico) é considerado um fator importante associado com o risco aumentado de desenvolvimento do melanoma cutâneo. Acredita-se que nevos atípicos sejam lesões precursoras do melanoma cutâneo. Podem estar presentes em pacientes com múltiplos nevos melanocíticos (síndrome do nevo atípico) ou isolados e em poucas quantidades em um contexto não familial. Aparecem, geralmente, na puberdade e prevalecem em indivíduos jovens. Têm predileção por áreas expostas ao sol, especialmente, o tronco. O grande desafio em relação ao nevo atípico reside na controvérsia em se definir sua nomenclatura, diagnóstico clínico, critérios dermatoscópicos, diagnóstico histopatológico e aspectos moleculares. Esta revisão tem por objetivo trazer o conhecimento, facilitar o entendimento e responder às questões duvidosas concernentes ao nevo atípico.<br>Atypical nevum (dysplastic) is considered an important factor associated with increased risk of developing cutaneous melanoma. It is believed that atypical nevi are precursor lesions of cutaneous melanoma. They may be present in patients with multiple melanocytic nevi (atypical nevus syndrome) or isolated and in small numbers in a non-familial context. The disease usually begins at puberty and predominates in young people. It has a predilection for sun-exposed areas, especially the trunk. The major challenge in relation to atypical nevi lies in the controversy of defining its nomenclature, clinical diagnosis, dermoscopic criteria, histopathological diagnosis and molecular aspects. This review aims at bringing knowledge, facilitating comprehension and clarifying doubts about atypical nevus

Melanoma Epidemiology and Prevention.

The epidemiology of melanoma is complex, and individual risk depends on sun exposure, host factors, and genetic factors, and in their interactions as well. Sun exposure can be classified as intermittent, chronic, or cumulative (overall) exposure, and each appears to have a different effect on type of melanoma. Other environmental factors, such as chemical exposures-either through occupation, atmosphere, or food-may increase risk for melanoma, and this area warrants further study. Host factors that are well known to be important are the numbers and types of nevi and the skin phenotype. Genetic factors are classified as high-penetrant genes, moderate-risk genes, or low-risk genetic polymorphisms. Subtypes of tumors, such as BRAF-mutated tumors, have different risk factors as well as different therapies. Prevention of melanoma has been attempted using various strategies in specific subpopulations, but to date optimal interventions to reduce incidence have not emerged